Prior to the present invention, as shown by Grover et al. U.S. Pat. 3,221,061, directed to a Method for Making Bisphenol A, a rearrangement reactor was used to convert by-product BPA isomers, such as o,p-bisphenol A to p,p-bisphenol A to improve overall BPA product yield. As shown by Mendiratta, U.S. Pat. No. 4,400,555, assigned to the same assignee as the present invention and incorporated herein by reference, improved reactant effluent product distribution was achieved in bisphenol A synthesis by using multiple acetone injection in an ion exchange catalyzed BPA synthesis process.
The present invention is based on my discovery that enhanced acetone conversion and improved BPA productivity can be achieved in bisphenol A synthesis by diverting part of the acetone, normally fed to the condensation reactor, to the rearrangement reactor. I have further found that if the amount of acetone diverted is held within certain limits, as defined hereinafter, the product distribution of the condensation reactor effluent can be substantially maintained. Improved efficiency in the production of bisphenol A is realized as the result of such higher acetone conversion.